Earth-moving machinery



Dec. 26, 1944.

J. 8. BURNS EARTH MOVING MACHINERY D6026, 1944. .s BURNS 2,365,677

EARTH MOVING MACHINERY Filed May 16, 1941 5 Sheets-Sheet 2 ATTORNEY Dec. 26, 1944. J! BURNS 2,355,677

- mm HOVING IAGHINEKY Filed lay is, 1941 s Sheets-Sheet 3 Patented Dee. 2c, 1944 UNITED. STATES PATENT, OFFICE EARTH-M022 1 llacnmnar John Stephen Burns, Bur-wood Park, Walton-on- Thames, England Application May 16, 1941, Serial No. 393,819 In Great Britain May 21, 1340 5 Claims. (01. 37-144) This invention relates to earth moving machinery with more especial reference to bulldozers, angledozers, trailbuilders or bullgraders in which an 'earthmoving blade is adiustably carried in front of a self-propelled vehicle of crawler or tractor type by the track subframes thereof.

Various forms of blade carriage have been proposed employing a yoke or U frame embracing the front of the tractor and pivotally mounted on the track subframes so that by fluid pressure or other mechanism the yoke may be raised or lowered to adjust the depth or cut. Two main disadvantages are however inherent to the existing track mountings of the blade carrying yoke or frame, the first being operational in that the blade rake and camber is unavoidably altered each time the depth of cut is adjusted and the other being structural in that the normal oscillation of the tracks about the axis of their rear sprockets (or about their axis of oscillation-if this does not coincide with the axis of the sprockets) when traversing inequalities is impeded by the mounting of the yoke which is correspondingly stressed under such conditions.

Although proposals have been made to obviate this structural defect the operating disadvantage remains and the present invention has for its ob-' ject to provide an improved blade carriage for bulldozers and like earth moving machines, with which both the structural and operational disadvantages are removed.

Further and iavourable objects will appear from the following description.

of the mouldboard and blade will be set to the optimum position, and this position will be main tained throughout the range of vertical movement of the blade when adjusting the depth of cut, such movement being conveniently effected from the operators seat on the tractor through tor is such that the tracks oscillate about the axis of their rear track sprockets, the axes, 1. e. the lower link trunnions of the blade carriage,

.are coincident therewith. In other cases where the respective tracks oscillate relatively to each other and to the tractor main frame about an axis on the main frame difierent from that of the the medium of fluid pressure cylinders carried by the main frame.

Preferably, where the construction of the tracrear sprockets, the trunnions for the blade carriage are conveniently coincident with such axis of oscillation. By mounting the blade carriage directly on the track subframes, the advantage is obtained that t e blade thrust is applied to said subframes withoutstressing the main frame.

The top links are conveniently pivoted to members on an axis approximately perpendicularly above the axis of the rear track sprockets or the alternative axis containing the carriage trunnions.

The carriage is completed by the front cross member of the yoke which for angle dozing is V-shaped and at the forward extremity whereof is the mouldboard and blade, which member has at each end uprights pivoted to the respective pairs of side links and, since-owing to the parallel linkage--the inclination of these uprights in relation to the tractor frame is constant irrespective of the setting of the carriage, the rake and eliminatesources of vibration. Conveniently, the rams of the fluid pressure cylinders, by which movement of the carriage is efiected, operate through hell cranks or rocking plates fulcrumed on the main frame of the tractor and operatively connected to the front cross member of the blade carriage by drop anns whereby it is unnecessary to compensate the fluid pressure system for oscillations of the track.

The mouldboard and blade may be articulated or universally mounted at the centre of the front cross member, conventional or appropriate means being furnished adalacent each end of the blade for adjusting the angle of incidence or dozing angle, i. e., the position in a horizontal plane, rake i. e., the inclination from the vertical, and camber i. e., angle of the blade when viewed from the front, preparatory to the commencement of work, although preferably the mouldboard and blade is simply mounted on a vertical hinge pin carried n t e cen re oi the front cross member which as aforementioned is V-shaped so as to permit the blade to be swung in a horizontal plane from the bulldozing position in which it is at right angles to the longitudinal axis of the tractor to angular positions for angledozing to spoil at either side of the tractor, adjusting links or thrust arms being furnished which extend from the ends of the mouldboard or blade and engage with brackets carried by the front cross memberof the carriage temporarily to flx the blade'in any of its adjusted positions.

The invention will be further described with reference to the accompanying explanatory drawings which illustrate by way of example one embodiment of improved blade carriage or mounting applied to a 'tractor of the type in which the tracks oscillate about the axis of the rearsprockets, and in the drawings:

Fig. 1 is a side elev equipped and Fig. 2 and Fig. 2A together constitute a'plan view showing how the mould-board and blade may be shifted from the bulldozing to the angledozing position.

Referring now to the drawings, I generally designates the main frame of the crawler-type tractor mounting the engine unit 2 and operator's seat 2, and 4 and 5 designate the crawler tracks which are mounted on track subframes designated 6 and 1 respectively.

tion of the tractor so Projecting laterally from the rear of the main frame I aredriving axles 8 and 9, mounting sprockets II! respectively which in turn drive the crawler tracks 4 and 5. In the type of tractor illustrated, the track subframes 6 and I are arranged, when traversing uneven surfaces, to oseillate about the axis of the rear track sprockets I II and so are journalled at I2 respectively to the axles 8 and 9, diagonal braces (not shown) being also furnished to withstand any torsional aseaevv to adjust the depth of cut, being coincident with the axis of oscillation of .the tracks 4 and 5, any likelihood of the carriage impeding the normal operation of the tracks when traversing uneven surfaces is avoided. Moreover in existing plant the rake and camber of the mouldboard and blade is unavoidably altered when the depth of cut is adjusted and to obviate this disadvantage resort is had in the embodiment of carriage illustrated to parallel Hm, the side arms 22 and 22 forming the lower links and complementary upper links 22 and 21 being furnished pivoted at their rear ends on trunnions 22 and 29, carried respectively by brackets 22 and 2| provided for the purpose at each side of the rear end of the main frame I perpendicularly above the axles 2 and 9 of the rear sprockets. At their forward ends the complementary links 22, 26 on the near-side and 22, 21 on the oil-side are connected by members 22 and 22 in the form of uprights or standards which are an integral part of the front cross member or apron IS, the

side arms 22 and 22 being hinged to the cross member by the pins 24 and 25 aforementioned,

and the upper links or side arms 26 and 21 beings similarly pivoted to the upper extremities of the uprights 22 and 22 by hinge pins 24 and 25 respectively.

With the links or side arms horizontal, as shown in Fig. 1, the uprights 22 and 22 are vertical or approximately so, and since the stationary axes of the links are disposed vertically one above the other, the uprights remain vertical strains and shocks to which the journals and axles would otherwise be subject when negotiating uneven ground or meeting an obstruction. These are standard features of the tractor which, it will be appreciated, are illustrated purely by way of example and as the invention is applicable to other types of tractor further detailed description of the particular construction of the tractor itself is unnecessary.

I4 indicates the mouldboard, conventionally of mild steel, and I5 its blade, advantageously of special alloy steel, the mouldboard having at its rear a. central bearing bracket I6, permitting it for angledozing to -be swung in a horizontal plane about a hinge |pin l1, in turn carried at the for- .ward central extremity I8 of a V-shaped transom or apron I9 forming the front cross member of the carriage.

The blade carriage is pivoted directly on the track subframes on an axis coincident with their axis of oscillation, i. e. the axis of the rear sprockets I0, and to this end there are attached to the rear of the track subframes i and 1,'secondary journals or trunnions 22 and 2| co-axial with the main journals I2 and pivotally mounting side-arms or lower links 22 and 22 which extend forwardly along each side of the tractor outside its track 4 and 5 and are bridged at their front ends by the aforementioned cross member I9, being attached thereto. by horizontal hinge pins 24 and 25 for the purpose now to be explained.

The trunnions 22 and 2! upon which the blade carriage is mounted for pivotal movements to raise and lower the mouldboard I4 and-blade II 22 when the linkages are oscillated up and down by 'the hydraulic system hereafter described to raise or lower the mouldboard I4. Consequently, as the mouldboard I4 is carried by the front cross member I2 of which the uprights 22 and 22 are integral parts, its rake camber and dozing angle remain. constant throughout the vertical range over which it may be moved to adjust the depth of cut.

For adjusting the depth of cut, fluid pressure cylinders 26 and 21, which may be conventional, are provided in conjunction with an enginedriven pump 22, reservoir 29 for hydraulic medium and control valve 40.

The cylinders 26 and 21 are at their rear ends fulcrumed to brackets H and 42 on the main frame I of the tractor at each side of the operators seat 2 and the rams or piston rods 42 and 44 are connected to rocking plates 45 and 46 which are adapted to oscillate about trunnions or hinges 41, carried by the main frame I of the tractor at each side of and in rear of the engine unit. The forward ends of the rocking plates 45 and 46 carry drop links or arms 49 and ill, connected to the front cross member or apron I! to raise and lower such cross member and with it the mouldboard I4 as the plates 45 and 42 are rocked about their hinges 41 by the fluid pressure medium being pumped into the front or rear ends of the cylinders 26 and 21 by the pump 28 onactuation of the control valve 42.

It will be understood that the rams or piston rods 43 and 44 normally work in unison so that branch ducts from the valve 42 may serve both cylinders, and the arrangement of the valve and fluid pressure system is preferably such as to afford four operative positions:

(1) Holding the carriage stationary;

(2) Admitting fluid under pressure to the rear ends of the cylinders to lower the mouldboard l4;

(3) Admitting fluid under pressure to the front asses ends of the cylinders to lift the mouldboard I4 and v (4) A free or floating position in which. the carriage falls about its rear trunnions l2 until the blade (5, or "mushrooms" conventionally mounted in rear of the mouldboard, come into contact with the ground or some other obstruction. 1

Moreover it will be appreciated that by pivoting the fluid pressure cylinders 36 and 31 and the rocking plates {15 and 46 to the main frame I of the tractor, instead of in the conventional way to the track frames, it is unnecessary to make provision for the transfer of fluid from one cylinder to the other to compensate for relative oscillation between the tracks and further that the camber, i. e. the angle of the blade in a transverse plane remains constant in relation to the axis of the rear sprockets, irrespective of the movements of the tracks when traversing uneven ground.

As aforementioned in addition to the vertical movement of the mouldboard 14 for adjusting the depth of out which is effected by the control valve 40 through the medium of the fluid pressure system, the mouldboard and blade are adjustable in a horizontal plane and the preferred embodiment illustrated affords the mouldboard three positions as now to be described with more particular reference to Fig. 2. The mouldboard M has a central bracket [6, carried by a. hinge pin ll, mounted at the front centre of the V- shaped cross member M as already described, and for bulldozing the mouldboard is fixed in a position at right angles to the longitudinal axis of the machine by adjusting arms 55 and t and, locating pins 57 and 5B, which as shown in the bottom left-hand corner of Fig. 2, engage coincident apertures provided for the purpose in the arm 55 and the mouldboard M on the one hand, and in the arm 55 and a'projecting lug 59 formed for the purpose on the standard 32 on the other hand.

Each adjusting arm is furnished with two further apertures and, after withdrawing the locating pins, the mouldboard l4 may be swung manually to its position for angledozing to either side of the machine, Fig. 2 in its upper half showing the blade set for angledozing to the off-side .with locating pins 6i and E2 in the two foremost apertures in the arm 56 and respectively engaging the mouldboard aperture and that furnished in a lug 60 on the standard 33 which is complementary to the lug 59 on the standard 32. In this position, as will be understood, the locating pin 5b in the near side of the machine would fix the rearmost aperture in the side-link 55, coincident with the aperture in the lug 59.

The carriage of the mouldboard is subjected to side-thrust when angledozing and to stabilise its forward portion during this operation, rubbing or cheek plates 63 and M are mounted on the track subframe 6 and 7 respectively and on these rubbing plates, which have vertical wear surfaces outside the tracks t and 5, ride rollers 85 and 66 carried by and on the inside of the channel-shaped side-arms 22 and 23. The rubbing plates which are mounted on the'track subframes as far forward as possible have supporting webs or yokes 61 and 6B bridging the tracks in the embodiment illustrated, although it will be understood that where thereis sufiicient clearance between the upper track rollers and the front idler, such re-inforcing webs may be located inside the track and still afford the rubbing plates adequate re-inforcement to retain their wearfaces perpendicular under the most severe sidethrusts likely to be encountered. when employing the machine as an angledozer. The side-arms or lower links which during the working of the machine, are in compression are advantageously of channel section with the channel web outside, and the upper links 25 and 21 which when the machine is working are owing to the form of the front cross member in tension, are advantageously of T-section, all as shown. H and 12 are intermediate links respectively bridging the upper and lower nearside horizontal links 22 and 26, and the off-side horizontal links 23 and 21, between their rear trunnions and their front ends carrying the cross member l9 and the mouldboard ll. As shown, each link has two limbs'converging from the bottom where they embrace the upper web of the channel section side-arm to the top 'where they lie on each side of the main web of the T-section, appropriate bushes being welded on to the parts to form the requisite bearings for the hinge pins.

The design throughout lends itself to cheap and rapid fabrication from rolled sections and in the lower right hand corner of Fig. 2 is shown how the mounting for the secondary journals or trunnions 20 and 2! may be built up from mild steel plate by welding. To facilitate attachment and removal of the blade carriage as a unit, running plates E9 and in are detachably connected' by bolts to the track subframes 6 and l and extend along the respective outer flanges of such subframes. Attached by welding to the external surface of the running plate 63 around the hub or main journal l 2 is a web it cut-and shaped so as to bridge the hub-cap it. To this web are attached by welding two rectangular plates Eli and 76, spaced by a packing Tl so a to accommodate between them an eye-piece '18, formed from a drilled plate and welded at 19 to the channel of the side-arm 22 to form the hinge thereof. A journal pin 80 completes the assembly which possesses the inherent advantage that the journal pin is in double sheer between the plates l5 and l By the present invention an improved blade and the like is obtained which may be cheaply and rapidly manufactured, readily attached to or removed from its vehicle and with which conven ience and durability in operation are assured.

What I claim is:-

1. An earth-moving machine provided with track sub-frames on each side of the same, an earth moving blade adjustably carried in front of said machine by members extending substantially parallel with said track sub-frames, said members comprising a parallel linkage, the lower links of said linkage being trunnioned to each sub-frame near the rear end thereof, the upper links of said linkage being mounted on trunnions carried by the main frame of said machine, a transom member carried by said linkage and forming the mounting for the blade proper whereby the depth of cut made by said blade may be regulated by angular movement of said linkage without changing the blades rake and camber.

2. In an earth-moving machine, a blade, at carriage for such blade adapted to embrace the front of a, crawler-type tractor having independent track subframes said carriage comprising a parallel linkage at each side of the tractor extending longitudinally outside each track subframe.

trunnion; for such links at the rear of the trantor fixed in relation to the frame thereof, front uprights pivotally bridging the front ends of each pair of side links, and a cross-member rigidly connecting said uprights and mounting the blade. 3. In an earth-moving machine, a blade carriage according to the preceding claim 2 wherein the blade is mounted on the front cross member below the pivotal attachments of the uprights t0 the lower side arms of the linkage so that in use the upper side arms are in tension.

4. In an earth-moving machine, a blade carv riage according to claim 2 having fluid pressure frame and drop slung from such rockers and connected to the front cross member carry- .ingthehlade.

ages carried by the uprights bridging the front ends of the parallel linkages.

JOHN STEPHEN BURNS. 

